Just been browsing parts and seen these

https://mastertrade.co.uk/fusebox-it1002u-100a-2p-connector.html

Wondering if in some cases they are a more elegant way of effectively splitting the supply to two consumer units.

Run supply into first unit and then use one of these to connect to the second unit. Struggling to get my head around how I would connect inside the consumer unit and maintain a supply capable of carrying ideally 100 amps.

Presumably the bus bar is ok if the connector is next to the incoming device, second board would use another one of these instead of a switch.

Then presumably use a short internal neutral cable from hager or similar from the neutral bar.

Wondering why I haven't seen others doing something like this. I am mainly looking at EV installs.

I assume these are aimed at when CU's are stacked and enabling effectively internal interconnection, where as for me I would probably have the boards next to each other, maybe with a gap.